Preheat oven to 400 degrees F. Using a 2-inch round fluted pastry cutter, cut 2 circles from each bread slice. (Reserve scraps for crumbs). In small saucepan, melt butter and and add thyme. Brush bread circles with this mixture. Place on a cookie sheet and bake 10 minutes, until golden. Meanwhile, combine shrimp with cheese, mayonnaise, bread crumbs and salt. When circles are cool, put a rounded Tablespoon of shrimp mixture on each. Sprinkle with a pinch of dill and place under broiler for about 3 minutes.